Vehement Fire of Charity

Today is the feast of St. Catherine of Genoa, who devoted her life to the sick and ran a hospital. She died in 1510. Her most famous and lasting work, however, is her Treatise on Purgatory, which is probably the most important early modern discussion of the doctrine. It appeared, four decades after her death, in a book about her life; the authenticity of the attribution to her has occasionally been denied, but the evidence, such as it is, tends to favor it, and there is no particular reason other than the work's late public appearance to reject it. It is usually thought, however, to have had some redaction by others, probably at least organizational. From the Treatise on Purgatory, chapter III:

And because there is no good except by participation with God, who, to the irrational creatures imparts Himself as He wills and in accordance with His divine decree, and never withdraws from them, but to the rational soul He imparts Himself more or less, according as He finds her more or less freed from the hindrances of sin, it follows that when he finds a soul that is returning to the purity and simplicity in which she was created, He increases in her the beatific instinct and kindles in her a fire of charity so powerful and vehement that it is insupportable to the soul to find any obstacle between her and her final end; and the clearer vision she has of these obstacles the greater is her pain.

Since the souls in Purgatory are freed from the guilt of sin, there is no barrier between them and God save only the pains they suffer, which delay the satisfaction of their desire.

[St. Catherine of Genoa and Don Cattaneo Marabotto, The Spiritual Doctrine of Saint Catherine of Genoa, TAN (Rockford, IL: 1989) pp. 303-304.]